Preliminary investigation of Toro and Nsukka stations from the Nigerian National Network of Seismographic Stations (NNNSS) with respect to Signal-to-Noise-Ratios (SNR) has been performed from noise observation and numerically. The results showed that Toro has higher SNR compared to Nsukka. Six months data collected from the stations in 2012 were used for the study. Nsukka Station in the southern part of Nigeria exhibited high noise than its Toro counterpart that is located in the North. This study is intended to investigate the causes of differing SNR at as observed at Toro and Nsukka stations respectively, with a view to adopting measures to forestalling SNR compromise at future stations in Nigeria.